Патент USA US2409076код для вставки
Oct. 8, 1946. A. M. sTARcK _ 2,409,075 EXTENSIBLE STAND ' Filed Nov. 18, 1944 4’ Ed m . V E N To R BY 0.1470‘, ’W ORNEYS . Patented Oct. 8, 1946 ' 2,409,075 UNITED. STATES PATENT OFFICE vArthur M. Starck, Stamford, Conn. , Application November 18, 1944, Serial No. 564,110 2 Claims. (Cl. 248-161) , This invention relates to adjustable stands and more particularly to stands for lamps, micro phones, music supports and the like. _ , . 2 . embodied in a lamp in secured in a customary manner at the endof a cross? arm ll of a post 12 which is mounted on top of an upper telescope Stands for lamps and the like have been made tube I3. The tube l3 telescopes within a lower vertically adjustable by various constructions which usually employ clamping screws that have the disadvantage of requiring loosening and tube M which has an inner diameter onlyslightly greater than the external diameter of the tube [3. The tube 14 is vertically supported by suit able means such as a base 15. It is desirable to tightening each timeit is desired to change the provide means for preventing relative rotation height adjustment. Screws are furthermore difficult to operate and detract from the appear 10 between the tubes [3 and I4 and for such purpose a spline or longitudinal ridge [6 is formed in ance of the stand. The unbalanced weight of the the wall of the tube l3 and a corresponding co vertically movable part of a stand causes con operating groove is formed in the tube '| 4, ‘ siderable eifort to be required to raise it and The function of the counterbalance device‘is also makes it di?icult to obtain accurate adjust 15 to stabilize the weight of the movable part of the stand, that is, the tube l3 and the parts supported Principal objects of the present invention are thereon. The counterbalance device is disposed to provide an improved stand for'lamps and the entirely within the tubes 13 and i4, and it includes like which is easily adjustable ‘in height, which a helical torsion spring I‘! having its lowerend needs only to be pushed down or up to adjust its height, and which will remain at the adjusted 20 secured by a bolt l8 to the lower end of the tube [4. A spacer I9 is disposed between the Wall height without the use of clamping screws. of the tube l4 and the spring [1. The spring I‘! Other objects of the invention are to provide an extends to a point near the upper end of the adjustable stand of the type in which the upper tube l4 and has secured to its upper end a cap portion is vertically movable with respect to the lower portion; in which the Weight of the upper 25 piece 20 by engagement of the upper coils of the spring in threads 2| formed in the cylindrical portion is counterbalanced; in which the counter part of the cap. In the upper portion of cap 20 balancing device is completely enclosed within there is provided a slot-shaped opening 23 the telescoping tubular members of the.stand; and longer dimension of which is substantially equal in which a spring is employed as a counterbalanc ing element in such a manner that the variation 30 to the inner diameter of the cylindrical part of the cap piece. in force exerted by the spring may be compen Through the slot 23 extends an auger-like or sated. ribbon-like spiral member 24 such as may be Other objects of the invention will in part be formed by twisting a rectangular flat strip of obvious and will in part become apparent from the metal. The twist or pitch of the spiral however, following detailed description of one embodiment is not uniform for reasons hereinafter described. thereof, in which: The length of the spiral member 24 is slightly Figure l is an elevational view of an exemplary greater than the length of the spring l1 and it lamp stand according to the invention, with parts extends upward into the tube I3 to which it is broken away to show the interior construction; Figure 2 is a view of a section taken on the 40 anchored at its upper end. A stud 25 is secured to the inside wall of the tube [3 and the end of line 2-2 of Figure 1 showing the upper anchor the stud is threaded to receive a nut 26 which of the counterbalance device; clamps the upper end of the member 24 to the Figure 3 is a view of a section taken on the line stud. When the member 24 is forced into the 3—3 of Figure 1 showing the counterbalance and means to prevent relative rotation between tele 45 spring H, the cap 20 is rotated and such rotation twists the spring I'I. When the member 24 and scoping members; tube l3 are stationary, the tension of the spring Figure 4 is a view of a section taken on the line I‘! reacts on the helical elements or surfaces of 4—4 of Figure 1 showing the guide between the the member 24 and tends to force it upwardly. spiral ribbon and the spring; and Figure 5 is a view of a section taken on the line 50 The pitch of the member 24 and the strength of the spring [1 are selected so that the upward ‘5-5 of Figure 1 showing the lower anchor of the force on the member 24 is suf?cient to balance counterbalance device. the weight of the tube I3 and elements carried As a preferred example the stand device of the thereby. present invention is incorporated in a ?oor lamp or bridge lamp. The device to be supported is 55 When a torsion spring is twisted, its tension ment. ' - ' . 2,409,075 3 4 is described herein only for purposes of illustra tion, but solely by the terms of the appended claims. What is claimed is: 1. In a telescoping stand having stationary and in most cases be constant. In order to compensate C11 movable relatively non-rotatable portions, a de for the effect of spring characteristic the pitch changes in accordance with the spring char acteristic. Therefore, the rotary force on the cap 29 changes at different positions of mem ber 24, but the weight to be counterbalanced will of the member 24 is varied so that it is coarser at the upper portion than at the lower portion. Thus when the cap, 2011s in the upper region of,v the member 24; the coarse pitch in conjunction with the greater tension of the spring l'l will pro; vide an upward thrust in member 24 which is about the same as the upward thrust which is obtained by the weaker tension in conjunction with the ?ner pitch when the cap Zlldsizi‘thelower region of the member 24. vice for counterbalancing the weight of the mov able portion, said device comprising a helical compression spring non-r‘otatably, secured at one end‘to' the stationary ‘portion, a cap member rigidly secured to the other end of said spring, and an elongated member non-rotatably secured at one end to the movable portion and provided with a helical element extending through and > threadedly engaging said’cap member to torsion said spring, said cap member reacting under the I While not essential, it is' found'advantageous to enclose the spring I‘! within a guide; tube. 23 in which the cap 20 and spring I‘! are rotatable torsional force of said spring to provide a vertical force'adapted to support the weight of said mov able portion. and which is secured between the spacer l9_ and 2; In a telescoping stand having stationary and the endof the spring H by bolt [8.’ A limited the spring ll as by givingthe lower end the . movable relativelyv non-rotatable portions, a. de vice for counterbalancing the vweight of the mov able portion, said device comprising a helical compression spring non-rotatably secured at one end to the stationary. portion, a cap member requisite number of‘ turns-before securing, it by rigidly secured to theother end of said spring, the bolt I82 and an elongated member non-rotatably secured at one end to the movable portion and provided with a helical element extending through and threadedly engaging said. cap, member to tor degree 7 of adjustmentv of the counterbalance de vice according tothe weight to be supported is obtainable by presettins the initial tension of 7 _ It will be seen that the, lamp may bemoved up and‘ down with equal. ease, that such» move ment will be smooth, and, that only, a minor ; amountof friction between the, movable and sta tionaryiparts su?icesito hold the lamp ?rmly in any adjusted position.‘ It. Wi11..,be, ' understoqdj that" the disclosure . described above, various, modi?cations may be madeiwithout affecting the. principle of thein vention; furtherthat theinvention is not to be considered as limited to the; embodimentwhich sionsaid spring, said cap member reacting under the torsional force of, said spring to provide a vertical force adapted to support the weight of said movable portion, said element having a vari able‘pitch, said pitch being greatest at the end farthest removed from the spring and least at the end which enters the spring. ARTHUR; M. STARCK.